Colon cancer is the second leading cause of cancer related death in the United States after lung cancer, and is the form of cancer most closely associated with diet. Both epidemiological and experimental evidence indicate that dietary factors in general, and dietary fiber and dietary fat in particular, are important in the etiology of colon cancer. Experts suggest that as much as 90% of colon cancer in the United States may be related to diet. Existing strategies for the treatment of colon cancer have produced disappointing results. However, the strong link between colon cancer and diet offers hope that progress can be made in reducing the incidence of colon cancer through changes in diet. Numerous investigators have examined the separate roles of dietary fiber and dietary fat in colon carcinogenesis, but little is known about the interactions of these two important dietary variables. The purpose of this research is to study the interactions of dietary fiber and dietary fat in colon carcinogenesis by feeding experimental diets containing four different levels of dietary fiber and three different levels of dietary fat to rats with chemically induced colon cancer. The results will be analyzed to establish the existence of dose-response relationships between colon cancer and dietary fiber and dietary fat, and evaluated interactions between these variables. Two endpoints will be utilized to evaluate the interactive effects of dietary fiber and dietary fat: 1) changes in colonic cell proliferation (a short-term study), and 2) changes in tumor development (a long-term study). In order to obtain insights into the mechanisms by which colon cancer develops, determination of cecal pH, fecal pH, and fecal bile acid content will also be performed. An important aim of this research is to provide opportunities for minority students to become involved in the research process. Minority biomedical students will receive training and experience in both the laboratory and non-laboratory aspects of scientific research. This project is designed to provide participating students with a strong background in nutrition and disease prevention, and to motivate them to pursue careers in the biomedical research.